Constrained function-based message authentication for sensor networks

Sensor networks are vulnerable to false data injection attack and path-based denial of service (PDoS) attack. While conventional authentication schemes are insufficient for solving these security conflicts, an en-route filtering scheme, enabling each forwarding node to check the authenticity of the received message, acts as a defense against these two attacks. To construct an efficient en-route filtering scheme, this paper first presents a Constrained Function-based message Authentication (CFA) scheme, which can be thought of as a hash function directly supporting the en-route filtering functionality. Obviously, the crux of the scheme lies on the design of guaranteeing each sensor to have en-route filtering capability. Together with the redundancy property of sensor networks, which means that an event can be simultaneously observed by multiple sensor nodes, the devised CFA scheme is used to construct a CFA-based en-route filtering (CFAEF) scheme. In addition to the resilience against false data injection and PDoS attacks, CFAEF is inherently resilient against false endorsement-based DoS attack. In contrast to most of the existing methods, which rely on complicated security associations among sensor nodes, our design, which directly exploits an en-route filtering hash function, appears to be novel. We examine the CFA and CFAEF schemes from both the theoretical and numerical aspects to demonstrate their efficiency and effectiveness. Moreover, prototype implementation on TelosB mote demonstrates the practicality of our proposed method.